ohbrdhntr, thanks so much for your effort in sharing this info.
The 3rd link you sent shows a blueprint of the Hession Type 3 forearm, clearly labeled "HESSION TYPE FOR FIELD GRADE GUNS". It is 9.650" long, same length as stated in Mr. Schwing's book. Section B-B of that print shows the cross-section of the forearm at the front end. It shows the forearm is exactly on line with the centerline of the barrels.
So, if you have a really slim forearm, ~11" long, that extends about 1/4" above the CL of the barrels, what is it? Rhetorical question..... humm. Silvers